yield WaitForSeconds(1) ends with this error:ArgumentException: method return type is incompatible

Questions & Answers
1

I just started with the UI in Unity and now i created a working menu with some Buttons. Now i wanted to add a delay with WaitForSeconds(1); in my JavaScript so that if i click one of the buttons it takes a scecond until they load the new Scene. How i made my buttons:
I created a canvas and added the Buttons with GameObject–>UI–>button then i created this JavaScript:

    #pragma strict
    
    function Start () {
    
    }
    
    function StartGame() {
    Application.LoadLevel(1);
     }       
    function Beenden(){
    
    Application.Quit();
    }
    
    function Anleitung() {
    Application.LoadLevel(2);
    }
    function Optionen() {
    Application.LoadLevel(3);
    }

I added this script to the Main Camera and added the Main Camera to the Buttons:
![alt text][1]
For every button i choosed one of the functions. My problem is when i add the command WaitForSeconds(1); to one of the funtions and click the button with this function i get this Error:

ArgumentException: method return type is incompatible
System.Delegate.CreateDelegate (System.Type type, System.Object firstArgument, System.Reflection.MethodInfo method, Boolean throwOnBindFailure) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System/Delegate.cs:190)
System.Delegate.CreateDelegate (System.Type type, System.Object firstArgument, System.Reflection.MethodInfo method) (at /Users/builduser/buildslave/mono-runtime-and-classlibs/build/mcs/class/corlib/System/Delegate.cs:276)
UnityEngine.Events.InvokableCall..ctor (System.Object target, System.Reflection.MethodInfo theFunction) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:99)
UnityEngine.Events.PersistentCall.GetRuntimeCall (UnityEngine.Events.UnityEventBase theEvent) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:355)
UnityEngine.Events.PersistentCallGroup.Initialize (UnityEngine.Events.InvokableCallList invokableList, UnityEngine.Events.UnityEventBase unityEventBase) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:518)
UnityEngine.Events.UnityEventBase.RebuildPersistentCallsIfNeeded () (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:679)
UnityEngine.Events.UnityEventBase.Invoke (System.Object[] parameters) (at C:/buildslave/unity/build/Runtime/Export/UnityEvent.cs:715)
UnityEngine.Events.UnityEvent.Invoke () (at C:/buildslave/unity/build/Runtime/Export/UnityEvent_0.cs:53)
UnityEngine.UI.Button.Press () (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Button.cs:35)
UnityEngine.UI.Button.OnPointerClick (UnityEngine.EventSystems.PointerEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/UI/Core/Button.cs:44)
UnityEngine.EventSystems.ExecuteEvents.Execute (IPointerClickHandler handler, UnityEngine.EventSystems.BaseEventData eventData) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:52)
UnityEngine.EventSystems.ExecuteEvents.Execute[IPointerClickHandler] (UnityEngine.GameObject target, UnityEngine.EventSystems.BaseEventData eventData, UnityEngine.EventSystems.EventFunction`1 functor) (at C:/buildslave/unity/build/Extensions/guisystem/UnityEngine.UI/EventSystem/ExecuteEvents.cs:269)
UnityEngine.EventSystems.EventSystem:Update()

Whats the problem can someone please explain how to fix this in a easy way because im very new to Unity and Java.

2

WaitForSeconds can only be used with a yield statement in coroutines.

Based on what you described, it is time for you to learn about coroutines

https://unity3d.com/learn/tutorials/modules/intermediate/scripting/coroutines

3

I advise you to use Invoke in this case, which is simpler and gets the job done:

Invoke(“MyFunction”, 2); //2 is the number of seconds

function MyFunction(){
Application.LoadLevel(1);
}

Of course it is advisable to use Coroutines (and to switch to C# in that case) for later, more advanced control.